Method of extinguishing fire



may 27, i939. e. c.v Hiss METHOD OF'EXTINGUISHXNG FIRE Filed March 29, 1924 mmv/ANA Patented May 27, 1930 UNITED STATES PATENT olv-'Fics GEORGE CROSBY ISS, OF EAST ORANGE, NEW JERSEY,l ASSIGNOR TO WALTER KIDDE 6a COMPANY, INC., OIEy NEW YORK, N. Y., A CORPORATION 0F NEW YORK METHOD OF EXTINGUISHING FIRE Application filed March 29, 1924. Serial No. 702,724.

Thisinvention relates to the use of noncombustible fluida-such as carbonicv acidfgas, in the extinguishing of fires, as described, for example, in Letters Patent of the United States No. 1,335,394,'dated March 30, 1920.

Such a fluid 'as carbonic acid gas is held in suitable containers in liquid form under high pressure and, when required for use in extinguishing fire, is discharged from the nozzle of the apparatus in gaseous form. The jet of gas, under the very high pressureof the liquid, vis discharged at very high velocity and, of' course, with more or lessdiil'usion or coning. The result has been heretofore that much atmospheric air, surrounding or laterally adjacent to thej et or jets, is entrained with the gas, with the further result that the gas is so diluted with the oxygen of the atmosphere that its fire extinguishing quality is greatly reduced. yThis phenomenon has been clearly recognized but hitherto no satisfactory way of preventing the entrainment of atmospheric air with the gas has been found. The object of the present invention is, therefore, to lprevent the entrainment of atmospheric air with the jet or jets of re extinguishing gas and this object is accomplished by i'nterposing between-the jet.`

of gas and the laterally adjacent atmospheric -air and in close contiguity tothe jet where the jet has its greatest velocity and therefore has the greatest "aspirating action and its principal eifect in entraining air, a protective shield or envelope which may be ofthe same or similar re extinguishing' gas in suiiicient quantity to supply such gas as is entrained by the jet and to maintain a gaseous shield between the jet and the adjacent atmospheric air, such shield conforming closely to the mai jet so long as its velocity is' such as to entrain air. As the gas of the jet reaches a substantial distance from the nozzle .its velocity is greatly reduced and its aspirating action is likewise reduced so that, the gas o the jet reaches the fire in a practically p ure state or so little diluted that its'ire extinguishing property is substantially unirnpaired. It will be understood that the described method.- can be practiced with various forms'of apparatus, adapted for use under different conditions. Several such forms of apparatus areV shown in the drawing in whichigure 1 is a view in longitudinal section an Figure 2 is an end view of a nozzle by which the main or central jet of gas is surrounded by other jets which form an envelope of gas about the central jet.

Figures 3 and 4 are'similar views but illustrating a nozzle of such construction that the central jet is surrounded by an annular envelope of gas. Figures 5 and 6 are views in front elevation and transverse section of a form of gas delivering apparatus or nozzle particularly adapted for application of the invention in extinguishing fire on the surface of a combustible liquid, such as oil, in an open tank.

Figure 7 is a diagrammatic and sectional view illustrating the use of the form' of nozzle shown in Figures 5 and 6.

Figures 8 and 9 are views in elevation and section illustrating'aJ modification of the gas delivering means shown in Figures V.5 and 6.

It will be understood that the iiuid to be used is suplplied from any sourceunder such pressure t at whether. it is in liquid form or in gaseous form within the conductor, it issuesfrom the discharge nozzle with considerablevelocity. Since the source of supply of the fluid is common and well known and is not itself involved in the present,l invention, it is not necessary that it be shown in the drawing.

Referring, first to the 'construction shown in Figures 1 and 2, the pipe a is the conductor through which is supplied, under pressure, the luid,either in liquid form or in gaseous form, which has, in its gaseous form, the property of extinguishing fire. The fluid is discharged in gaseous form from the conductor a, the main jet being discharged from a central nozzle b in the head or end cof the conductor a. It is this central jet which is' kmainly depended upon to' carry the extinof atmospheric air, bywhich the fire extinguishing gas would be diluted and lose something of its effectiveness. To prevent such entrainment of atmospheric air the main or central jet is protected by a shield which may be of the fire extinguishing gas and may be received from the same supply as the main jet, suchjshield conforming closely to the main jet so long as its velocity is suflicient to entrain air. For this purpose, in the construction shown in Figures l and 2, there are provided in the head c other orifices Which may be choked more or less and disposed around the centralorifice so that the gas which is discharged from the auxiliary orifices, being diffused, will form a shield between the main' jet and the adjacent atmospheric air in close contiguity to the said jet so long as the velocity of the said jet is otherwise sufiicient to entrain air to a harmful extent. If the auxiliary orifices are properly formed the gas which issues from themv will form -an envelope around the central jet, completely separating it from the surrounding atmosphere, although, as Will be seen, such complete enveloping of the main jet is not essential in some instances. By reason of the provision of such a shield whether of fire extinguishing gas or otherwise the main et will notentrain and carry on with it any such volume of atmospheric air, if any, as Will dilute the gas of the central jet to such an extent as to impair its fire extinguishing property to any substantial degree.

In some cases it may be desired to insure the delivery of a complete envelope of shielding gas and in igures 3 and 4 is shown a form of apparatus which accomplishes this result. In this embodiment of the invention through which a completely encircling envelope of gas is discharged around the main jet b2.

Fire extinguishing devices of the lclass to which this invention relates are found particularlydesirable for the protection of combustible liquids in open vats and for such uses the apparatus may be modified in form,

as shown in Figures 5, 6 and 7 and also in Figures 8 and 9. In the embodiment of the invention illustrated in Figures 5, 6 and 7, the conductor a4 is disposed within the tank e to be protected around and close to the sides thereof and is provided near its lower side with jet orifices b4 and above them with other jet orifices b5. From the orifices b4 are discharged the main jets of gas which are chiefly relied upon for extinguishing fire and from. the orifices b5. is discharged the gas which forms a protecting shield between the gas of the main jets and the atmospheric air conforming closely to the gas of the main jets and in close contiguity thereto and preventing the entrainment of air with the gas of the main jets. vention shown in Figures 8 and 9 is generally similar to that shownin Figures 5, 6 and 7 and is particularly adapted for the protection of inflammable liquid in a vat e but the main jets 66 may be formed in one pipe a5 and the auxiliary jets 67 may be formed in another pipe a placed abovethe pipe a5, the result, however, being, as before, the discharge of a protecting shield of fire extinguishing gas between the gas of the 'main jets and the laterally adjacent atmospheric air.

It will be obvious that. the invention may be practiced with other forms of apparatus and, except as pointed out in the claim, is not restricted to the particular 'forms of apparatus shown and described herein.

It will also be understood that while reference has been made to atmospheric air adjacent to the jet of fire extinguishing gas, the

The embodiment of the in-y adj acent gaseous body might be any combustion supporting gas.

.'Iclaim as my invention:

The method of extinguishing fire which comprises projecting a jet of fire extinguishing gas at a high velocity and interposing in close contiguity to said jet a protective shield of fire extinguishing gas between the jetk and the laterally adjacent atmospheric air so long as the velocity of said jet is otherwise sufficient to entrain air.

This specification signed this 24th day of March, A. D. 1924.

GEGRGE CROSBY HISS. y 

